Rivet setting mechanism



Dec. 3, 1940. L HUcK ,2,223,449

RIVET SETTING MEcHANIsM Filed May 14, 1935 '7 Sheets-Sheet l Dec. 3, 1940. L, c, HucK nIvE'r SETTINGMEGHANISM Filed May 14, 1935 7 Sheets-Sheet 2 INVENTOR. pas CZ Huc.

ATTORNEYS- Dec. 3, 1940. L C. HUCK RIVET SETTING MECHANISM Filed May 14, 1935 Dec. 3, l L, HUCK y2,223,449

RIVET SETTING MECHANISM Filed May 14, 1935 7 Sheets-Sheet 5 49am 4f 5 15,250 4 7/ fifi? 2 alle z I A524 Af/ f5 V J x 1 ?a INVENTOR. cuis 6. Hue/7:.

A TTORNEY.

Dec. 3., 1940. i C. HUCK 2,223,449

' RIVET SETTING MECHANISM Filed May 14, 1935 -7 Sheets-Sheet 6 9 INVENTOR. Louis 6. #uc/r. Jag BY El.g. ATTORNEYS.

Dec. 3, 1940. y l.. c. HUCK RIvET SETTING MECHANISM Filed May 14, '1955 '7.Sheets-Sheet 7 f5@ H M M #401cm -f/ff'l v l O ,J

@im ff Y l /6 6,5 F556 ,59 .56 if a r Patented Dec.. 3, 1940 i UNITED STATES PATENT oFFIcg 2,223,449 l mvn'r SETTING Mechanism! l Louis c. nook, Grosse Pointe village, moli., assignor to Huxon Holding Corporation, a cor porationofMichigan Application May 14, 1935, No. 21,472; f

1o claims. (ci. sip-54.5)

The invention relates to a rivet setting mechanism and it has particular relation to a mechanism for 'setting rivets of a type including a tubular element and a pin extending there- '5? through and which is inserted and set' from one side of the structure to be riveted.

More particularly the invention constitutes an improvement in rivet setting mechanisms over those disclosed in the copending applications for 10 patent of Louis C. Huck et al., Serial No. 615,544, filed June 2, 1932, now Patent No. 2,053,718, and Louis C. Huck et -al., Serial No. 636,480, med October 6, 1932, now Patent No. 2,053,719.

In the rst of the above mentioned copending 15 applications for patent a rivet setting mechanism was set forth which included a rivet setting gun and a uid pressureO boostingv device connected thereto by iiexibletubing so that the gunmight be used at points remote with respect an to the booster and without movingl the booster `each time the gun would be moved. It also was set forth in this application for patent that air l pressure would be used in the booster device for building up a liquid fluid pressure which would 23 be supplied to the gun for operating it during the rivet setting procedure. Y Moreover. this rivet setting mechanism was so designed and constructed that by manipulating a trigger on the gun, operation of the booster device and 'setting lI0 of the rivet could be controlled entirely by the operatormanipulating the gun even though the booster device would be located some distance away. j

In the last mentioned of the copending appliv85 cationsfor patent, a rivet setting gun of some-,-

` what different character is disclosed which also operates inv conjunction with a booster device such as set forth in the first mentioned cependv 'ing application for patent. The gun in the sec- A240 ond case includes'two pistons one of which op- .'erates rst when the trigger on vthe gun is pulled .to enect \a certain phase of the rivet setting operation and then upon completion of this phase, the second. piston automatically becomes oper- 45 'ative to cause an auxiliary anvil to move over .65 satisfactory. certain improvements have been` dem trigger or operating element on the gun.

sirable and `form the basis .of this invention. These may senerallybe indicated inthe objects of the invention but'a more detailed explanation will be found in the; description. Objects of the invention4 additipnal to those loutlined hereafter s will be apparent from this description, from'the drawingsto which lit relates ,and from the claims hereinafter set forth. One objectof lthis invention is to provide a rivet setting gun whichuis more efcient in vop.- n eration and which may more easily be handled and l manipulated by-thej operator. Another object of the linvention-is to provide an improved Jaw mechanism and operating arrangement therefor which will enable, using a smaller diameter of barrel on the gun and. also facilitate insertion of the Jaws during assembly of the gun. A

Another object ofv theinven'tion is -to provide an improved-rivet setting mechanism including 0 a riveting gun and a fluid pressure boosting device, wherein means are providedfor limiting the building up of liquid fluid pressures in the gun and booster even though the operator maintains the trigger on the gun in its rivet setting .25 position after completion of the rivet setting operation.

Another object of the invention is to provide an improved rivet. setting mechanism including a rivet setting gun and booster device wherein su a reservoir -is providedl in connection with the liquid uid side of the system for maintaining the liquid filuid spaces filled with liquid and for replenishing the iluid'supply at any time it is needed and particularly for supplying additional l315 liquid fluid in the event any vacuum tends t0 occur during" return of the booster piston in which event air would tend to seep into. the liquid. fluid sideunless liquid iluid were injected toinsure prevention of any vacuum spaces.

Another object of the invention is to provide an arrangement wherein upon completion .of the rivet setting operation or in any event where the liquid uid becomes subjectedto pressure above that necessary to set the rivet, the liquid 4 5 -fue1 may ilow into the reservoir. and prevent building up of an undesirably high uid pressure. Another object ofl the invention is to provide an improved'valve arrangement in the booster y device which. is'automaticsuy controlled .by the 5.0

Another object of the invention is to provide a mechanism, and particularly ariveting mechanismginvolving -theyuse offluid pressurere- ,spcxisive means. wherein automatic means is 55 employed for economizing on the iiuid required for operatingl the fluid pressure responsive means. v'

Another object of the invention is to provide an improved riveting gun or the like employing jaws therein, wherein means are provided for manually opening the Jaws.

Another object of the-'invention is to provide an improved system including a riveting gun and fluid pressure boosting mechanism. wherein liquid uid under high pressure is used to operate lthe piston in the pressure boosting device.

For a better understanding of the invention reference may be had to the drawings wherein:

Fig. 1 is a side elevational view of a riveting gun and fluid pressure boosting device constructed according to one form of the invention with the boosting device shown partly in cross section for the purpose of illustrating certain details thereof.

Fig. 2 is a cross-sectional view taken substantially along the line 2-2 of Fig. 1 but on an enlarged scale.

Fig. 3 is a cross-sectional view on a slightly smaller scale taken substantially along the line 3-3 of Fis'. 2.

FiFig. 4 is a plan view of the boo'ster shown by Fig. 5 is a cross-sectional view on a larger scale taken substantially along the line 5-5 of Fig. 6 is a cross-sectional view illustrating the barrel on the booster andthe reservoir and a valve arrangement associated therewith.

Fig. 7 is a cross-sectional view taken substantially along the line 1-1 of Fig. 6.

Fig. 8is alcross-sectional view taken substantially along the line 8--8- of Fig. 7.

Fig. 9 is a'vertlcal section on a larger scale of the riveting gun shown in Fig. 1.

Fig. 10 is an end view of the, riveting gun as seen from the left end of Fig. 9.

Fig. 11 is a cross-sectional view on a slightly larger scale taken substantially along the line II-II of Fig. 10.

Fig. 12 ls a cross-sectional view taken substantially along the line I2-l 2 of Fig. 11.

Fig. 13 is a cross-sectional view taken substan tially along the line I3-I 3 of Fig. 12.

. Figl 14 is a cross-sectional view taken substantially along the line I4-I4 of Fig. 9.

Fig. 15 is a cross-sectional view taken substan-` A struction therefor.

Fig. 21 is 'a cross-sectionaljview illustrating a different form jaw mounting in the riveting gun. Fig. 22 is a cross-sectional view taken substantially along une 22-22 of Fig.21. Fig. 23 is a cross-sectional View vol? a rivet adaptedto be set by the riveting mechanism illstrating the rivet as initially inserted through openings in a'structure to be riveted.

Fig. 24 is a similar cross-sectional view illustrating the rivet after it has been set.

In general the construction shown by Fig. 1

vby bolts 2| to this end of the cylinder.

comprises a riveting gun 8 and a pressure boosting device 9. Fluid under pressure, such as air, actuates the booster and the latter supplies liquid underv a greater pressure to the gun for operating the latter. Control of the mechanism is effected at the gun by means of a trigger valvev site sides the piston is provided with oppositely disposed cup-shaped sealing rings I4 around the outer edge for preventing uid under pressure from leaking past the piston, and these rings may be retained in place by slightly smaller ring plates I5 secured by bolts to the piston body and which press triangular wedge rings l5' into the cup grooves. A piston rod I8 projects through the piston and is rigidly secured thereto by means of a shoulder I1 on one side of the piston and -a nut I6 on the other. This rod projects'through an opening in the end wall I2 of the cylinder.

and is reciprocatory in a small barrel 20 secured Along the opening in the Wall I2 and in the adjacent end of the barrel, cup-shape sealing rings 22 are provided for preventing lfluid under pressure from escaping along the rod I6 and the rings at one side are disposed oppositely to those at the other side to provide a positive seal against uid escaping from the cylinder and barrel. 4Between the oppositely disposed sealing rings, a vent 23 is provided so that any air leaking from cylinder l0 past the first rings will be allowed to escape to the outside. The outer end of the barrel is connected to a high pressure hose 24 of flexible character which extends to the riveting gun and it 'should 'be understood that the barrel and hose will be filled with liquid fluid such as an oil suitable for thisl purpose and that when the piston rod I6 moves to the right this oil will be forced into the gun.

It may be mentioned at this time that the cylinder and barrel are mounted on a suitable frame ,26 which is supported at the barrel end by a caster 21 and at the opposite end by a pair of wheels 28 so that the booster can be readily moved from place to place whenever this is necessary The piston I3 is reciprocated by air under pressure and owing to the relatively large diameter of the piston as compared to the diameter of the piston rod and the barrel into which it projects.

a very highfpressure on the liquid fluidinl the barrel and hose 24 will be obtained when a relatively low air pressure is used in the cylinder.

For actuating the piston, a valve mechanism 30 is mounted on the left end wall I I of the cylinder,

and this mechanism as best shown by Figs. 2

and- 3 has an elongated bore 3| of substantially uniform diameter which terminates in a slightly V larger bore 32 at the right end thereof. Within the bore, a reciprocatory valve operating element 33 is provided whichhas piston-like heads indicated at 34, 35 and 36 respectively, which operate in the smaller portion of the bore 3l and closely t therein to prevent leakage, of air therepast. At the right end of `the element '33 a pin 31 is provided which projects into the head 36, and this pin terminates at its right end in a head 38 that is. reciprocatory in the larger portion 32 of the b'ore. This head has a projecting portion 39 of smaller diameter and around this projection a piston sealing ring 43 may be provided.-

The larger portion 32 o i the bore is closed at its outer' end by a cap 4I which is connected to a conduit 42.

At the left end of 'the bore 3l, a piston 43 is provided which is adapted to move the element 33, and this piston similarly to the piston 33 at the right end of the bore terminates in a smaller projection around which a piston seal is provided. Air is introduced to the valve by an air line 44 shown by Fig. 3, communicating with a longitudinal aperture 45 that extends to and communicates with the left end of the bore 3| at the left side of the piston 43 by means of an aperture 45 provided in a cap 41 that closes this end of the bore. Air may enter the bore 3l through an opening 43 adjacent the right side of the head 35 when the reciprocatory element 33 is at the left end of the bore. The space between the heads 35 and 35 lwhen the valve element'is in the position shown also is in communication with 'a conduit 43 by means of an opening 53,

and this conduit is adapted to introduce and discharge air to and from the right end of the cylinder I3 as will presently be explained.

The bore 3I immediately to the left of the head 35 is in communication with the left end of the cylinder by means of anV opening 5I extending through the `end wall II, and immediately to the right oi heads 34 and 35 openings 52 and 53 in the wall are provided to allow air at the left and right ends of the .cylinder to 4exhaust ,to atmosphere. With the parts in the position shown, air at the vleft side of piston I3 will exhaust linto the atmosphere while air under. pressure issupplied to the right end of the cylinder. I l

Upon movement of plunger 33 to the right, the

head 34 moves past exhaust port 52 and head 35 moves past opening 43 (Fig. 3), thereby allowing air to enter the leit end of the cylinder through opening 5I. At the same time, head 35 moves past port 53 and opens the port 53 and conduit 43 to exhaust, so that air may exhaust from the right end of the cylinder.

The conduit 43 for introducing air to and discharging it from the right end of the cylinder I3, as shown by Fig. 5, is connected to a cylinder 54 forming part of aneconomiser valve. Referring to Fig. 5, the cylinder 54 has a bore 55 prqr,spring 5I disposed in a tubular guide, which may be adjustably tensioned by a. screw 52 connected to theother end of the spring. Aroundvthe port 55, the bore has agroove 53 and a smiliar groove 54 is provided in spaced relation and to the left of thgroove 53.. The grooves 53 and 54 communicate-by means of passageways 55 and 55,

respectively, with a conduit 51, which, as shown by Fig. 1 extends to and isconnected to the right end of the cylinder I3. The passageway 55 has a spring pressed Sball valve 53i'or 'allowing air to.'

flow through thepassageway" from thev conduit 51 but preventing a reverse flow of the air.` A conduit N53, connected to-the conduit 51 and to the' left end of the cylinder, introduces uid under pressure from the conduit to the left end of the cylinder 54 and it` may be noted that the left end of the plunger 51 has a sealing ringto prevent fluid owing past this end of the plunger.

Assuming that the valves shown by Figs. 2, 3l

and 5 are-positioned as shown, the lettside'roi piston I3 is open to exhaust, and air under. pressure ows through conduit 43, and, as shown by Fig. 5, into port 55,- and then through port 55 into conduit 51 and to the right end of the cylinder I3. As the pressure builds up in the conduit 51,lt is applied through conduit 53 and against the left end oi the plunger 51 and the left end of the latter moves to the right and over groove 54 and cuts oi the supply. This movement occurs when the tension on spring 5I is overcome `and-.hy adjusting the screw 52 the cut oli may be varied. In this manner, only a part of the line pressure is used. While the plunger 51 might repeat its reciprocatory movement, owing to lowering of the pressure in the cylinder I3 as the piston I3 moves, 1t can be seen that the fluid utilized in returning piston I3 to the left is reduced in pressure and amount. After the piston I3 reaches the left end of the cylinder, plunger 51 will be at the right end of cylinder 54 and will remain there. An air vent is provided at the right end of cylinder 54 to avoid any trapping of air.v

When the plunger 33 in Figs.. 2 and 3 shifts to the right, the piston I3 will move to the right,

as soon as port 55 is open to exhaust and it will be understood that the ball valve will open under averylow pressure so that no appreciable air resistance to* movement of the ,piston I3 to the right is'present. As soon as port 55 is open to exhaust, the ball valve opens and the air pressure in conduit 51 drops and plunger 51 then returns tothe left,`so that conduit 51 may freely exhaust through the passageway 55.

Movement of the piston I3 to the right forces the piston rod I5 into the barrel 23 and this forces liquid in the barrel through the line 24 to the gun 3.

In view of the fact that certain parts on the barrel 23 are also controlled by air pressure, and that the conduit 42 is interrelated with these parts, it is necessary to first describe these Aparts on the barrel.

For the purpose of insuring that the liquid Aside of the system will be constantly illed`at all times, a reservoir 13 is provided as best shownby Fig. 6 which is iixed to the barrel 23. In this reservoirra piston 12, having a sealing ring 1.3, is provided which has a tubular stem portion 14 rciprocatoryin a tubular cap 15 closing the lower side of the reservoir. A sealing ring 15 held by a plate 11 seals the extension 13 as it enters the cap 15. The extension 14 acts as a small piston in the cap 15 and air under pressure is adapted to be admitted to the latter through a conduit 13 which is connected, as best Shown by Figs. l and 4,. to a four-way coupling 13 that in turn is connected by a conduit 33 to the air line 44. Thus constant air pressure will urge the piston 12 upl wardly although it will be noted that the force urging the pistonvupwardly is applied against-a much smaller piston working in the cap 15. For the purpose of pulling the piston 12 downwardly when liquid is introduced intol the system and reservoir, and also indicating the -amount of liquid in the reservoir, a rod 3|' passes freely vthrough the cap 15 and is connected to the piston. In order to prevent the operator from pulling the piston 12 all the way downwardly so that the reservoir would be completely lled, a pin 82, having av head 83 on its lower end, projects through the extension 14 and is threaded into the piston 12, and this pin has a sleeve 84 thereon which, in conjunction with head 83, holds a co1- 1ar-,85 adjacent the latter. An inverted cup 86 is slidably mountedon the lower end of the pin and sleeve 84,' and the upper end of the cup is normally urged downwardly against the collar, by a loaded spring 81'A encircling the sleeve. A weaker and pre-loaded spring 88 is disposed in the cup 86 and seats in a smaller opening in the base vof cap and also engages the lower side of the collar 85. This smaller opening also provides a Vspace for the' head 83, collar 85 and sleeve 34 to move into upon downward movement of piston 12. l

Assuming that no air pressure is present in the lower part of the extension 15, the operator in lling the systemA with liquid may readily pull the piston downwardly by means of the rod 8|, but this movement downwardly is resisted when the parts become positioned, as shown in Fig. 6, as the cup 86 engages the lower end of the bore in cap 15, and any further movement of the piston 12 is resisted by spring 81. This normally prevents the operator from so fllling thesystem that the reservoir is also completely filled. If it is necessary to displace liquid into the reservoir from the system during its operation, piston 12 may still move farther downwardly duringwhich the spring 81 will be compressed lengthwise. The spring 88 is provided so as to always maintain an upward pressure on the piston 12 and prevent the latter from moving downwardly when there is no air pressure in theextension 15 and when f the cup 86 is not resting on thebase of the-bore in the extension 15. Otherwise, with-the system' at rest, and Without air pressure in the extension 15, there would be a tendency for the 'piston to gravitate downwardly and create a partial vacuum which might cause air to be drawn in at some point in the liquid side of the system.

As shown by both Figs. 6 and 7, the `reservoir communicates with a side passage 98 turn communicating with a downwardly. extending bore 9| and the latter in turn communicates with a passageway 92 effected during provision of passage 98, and which is closed at its left end 'as shown by Fig. 6 by a plug 93. Adjacent the bore 9|, and as shown by Fig. 7, the barrel 28 has lateral projections 94 and 95 which are bored as indicated at 96 and 91 respectively. The bore 96 at its inner end has an apertured valve seat 98 adapted to be closed by a ball 99. A pin |88 slidable in la bushing I8| fitting in the outer end of the bore 96 is adapted to engage the ball and hold it on the seat 98, and the outer end of the pin has a head |82 which is slidable' in a cap |83 fastened to the projection 94 by bolts |84.l The head |82 isengaged by a pin portion |85 projecting froma head |86, also slidable in the cap, and which has a smaller portion A|81 slidable through the end vided on heads |82. and |86 to prevent air' between them from escaping, and s imilar rings are provided on bushing |8| to prevent liquid from escaping through bore 96 and around pin |88. It may be noted that the ring |89 at the outer side of bushing I8| is held in place by a plate I8.

The barrel 28 communicates with the space b e sure to such space.

At the opposite side of the passageway 98, a bushing I|3 is tightly secured in the bore 91 and a pin I |4 slidable in the bushing is adapted to engage the ball 99 and unseat it. The pin has a head ,I I5 reciprocatory in an enlarged portion |I6 of the bore 91 and the outer end of the latter is closed by a cap joint ||1 having an air passage 8 communicating with the space at the outer side of the head I5. Sealing'rings 9 are provided to seal against escape of liquid and air, Abut an air vent |28 is provided betweenthe bushing `I I3 and head I5 to prevent trapping of air.

'I'he passage I8 intersects a passage |22, which at its left end is connected to the conduit 42, while the right end of thepassage is connected to a conduit |23 extending lto the riveting gun 8. A metering pin |24 projects into a reduced portion |25 Vof passage |22 adjacent the inner end of conduit 42 -so as to adjustably vary the supply of air from passage |22 to the conduit. For supplying air to the connection, a conduit |26 (Fig. 8), connected to the four-way valve 19, is connected to a third passage |21 .which intersects passage |22, and an adjustable metering pin |28 projects into this third passage.

' In' spaced relation to the metering pins, another pin |38 slidably projects through the cap ||,1 and is adapted toengage the head ||5. A seal |3| is provided in a recess around the inner end of this pin to prevent escape of air and the outer end of the pin opening is closed by a screv.J |32. By removing the screw and applying pressure to the pin, the exact instant the head II5 is moved may be noted. This is desirable in that a sequence-of operation of the valve 38 and ball .valve 99 is desired, and in adjustment of the metering pins to obtain this sequence, it is necessary to knowwhen the head ||5` moves.

As shown by Fig. 6, the b ore 9| terminates at its upper end in a smaller opening which opens to the barrel 28'and the upper endfof the 'bore has a tubular element |36 closely tting therein which has an annular groove |31 in its outer surface and a plurality of radial openings |38 connectingthe groove to the open central part of the element. 'Ihe element 36 has a small opening |39 at its upper end whichjoins a lower and larger opening |48 and the latter opening has a valve stem I4I- reciprocatory therein which terminates at its upper end in a smaller portion |42 having a tapered edge adapted to close the lower end of the smaller opening |39. The upperV end portion' of the stem adjacent -the openings |38 has minutevertical grooves |43 extending from a. shallow annular groove |44 on the stem to the upper end of the larger portion of the stem. It may be added also that an annular groove |45 is provided in bore' 9| in communication with -openings 98 and 92. When the smaller end ,of

the stem is unseated by liquid pressure in the barnel 28, the pressure then also will be applied against the upper end ofthe larger portion of the stem, so that a pressure lower vthan that required to unseat the stem will' hold itl open. V Downward movement of the stem uncovers the .f

radialr openings |38 so that liquid ,Will ow A through opening 98 into the reservoir. The mi- *nute grooves |43 and groove |44 are provided so that if there should be anyslight leakage through the valve when it is closed, the leaking liquid may iiow into the reservoir instead of applying 8 pressure against the larger end ofthe stem and causing the valve to open. Such grooves are .too small, however, to appreciably vary the above mentioned and normal operation of the valve.

The element |36 is positively held in position 10 at the upper end of the bore 9| by a bushing |46 and collar |41 in turn engaged by a sleeve |48 threaded into the lower end of the bore. 'I'he sleeve |48 has a pin"| 49 vtherein terminating at its upper end in an annular flange |50 and a por- 1li tion |5| that is adapted to engage the lower end ofthe stem |4| and hold the valve stem in valve closing position. The pin |49 is urged upwardly by a very strong spring |52 that abuts at its lower end a screw cap |53 adjustably threaded onl the lower end of sleeve |48. Similarly to the construction shown by Fig. '1, sealing rings are provided, as indicated at |54, to avoid vescape of liquid or entry of air.

This valve construction provides a relief valve in the event the pressure on the liquid in the barrel 20 becomes undesirably greater than that required in the riveting operation, and particularly in the event the operator maintains the trigger on the gun released after the rivet is set,

in which event the liquid pressure would increase.

Referring now to Figs. 9 and 10, the riveting gun comprises a cylinder casting |10 having a thickened upper portion |1| upon which a handle |12 is detachably secured by means of bolts |13.

It may be stated at this time that the gun normally will be used with the handle uppermost and the latter is so arranged with respect to the cylin-A der casting and other parts'of the gun that a vertical line substantially through the center of 40 gravity o! the gun will pass upwardly substantially through the center of the handle so that the operator holding the gun suspended from the handle will iind the axis of the cylinder substantially horizontal. This adds to the ease with 48 which the gun may be manipulated and operated. The casting' |10 includes two bores |14 and |15 separated by an integral wall |16, and a tubular, piston rod |10 is journaled in a bearing |19 pro- 'vided in a central opening in the wall |16 for 50 reciprocatory movement axially of the bores. The bearing terminates at its right end in a flange |80 which abuts a shoulder |8| on the wall so as to prevent movement of the bearing towards the left, and at the right of the flange |80 a seal- 58 ing ring |02 of cup-shaped character is provided so as to positively preventfluid at the right side of the wall |18 from ilowing along the rod |18 to the left Yside thereof. A piston |84 is rigidly mounted on the rod' |10 within the bore |14 and a0 this piston has a sealing ring |85 'at its left side and around the rod to positively prevent iluid between the piston and the wall |16 fromflowing between the piston and pistonrod. The outer periphery of the piston is-provided with sealing rings |06 similar to those mentioned which prevent iluid from flowing between'y the cylinder wall and the piston periphery. At its right end, .the piston rod projects through a closure head |81 held against a shoulder |08 .-bya ring |89 threaded into the end of the cylinder, and thef'head, |81

has a bearing through which the rod"'pioje``:ts. The inner end' of this bearing is anged similarly to the bearing |19 and a sealing ring is disposed' in a recess -in the head to prevent iluid from now- 7.; ing between the piston rod and the head.

1n the bore |15 a similar piston |94 is provided but this piston has an inner bearing associ- `ated therewith which may reciprocate with the 200 that is held in the left end of the cylinder byl a threaded sleeve 20|. A sealing ring such as mentioned may be provided at the right side of 15 the head 200 to prevent iluid from escaping along the bearing.

At the left end of the tubular portion |98 of the piston |94, a head 203 is mounted for reciproeatery movement on the piston rod and a. bearing 20 204 may be provided between it and therod. This head has a tubular portion 205 slidable in bearing |99, abutting the portion |98 of the piston so that when the piston is moved to the left, the head 203 moves therewith.v

The head 203 at its left end terminates in three radially oil'set and axially directed legs 206 spaced degrees apart as best shown by Fig. 14, and these legs are'axially movable in recesses 201 formed in the cylinder head 200. Between the 130 recesses inwardly directed legs 208 are thereby formed n the head 200, as also shown by Fig. 9,

and it may be noted that the circumferential length of the recesses substantially is the same as thecircumferential length of the legs 208. Re- 35 ferring now both to Figs. 9 and 15, axially beyond the end of the legs 208, the head 200 terminates in a cylindrical portion 209 of larger diameter and this tubular projection has two slots 2 I0 spaced 60 degrees apart and which extend to the outer end 40 thereof. .An outer barrel sleeve 2|2 is reciprocable in the tubular portion 209 and the inner end of this sleeve at one point is provided with an outwardly directed projection 2|3 adapted selec tively to fit in one of the openings 2 l0. It will be 45 appreciated that the slot 2|0 will hold the barrel sleeve 2| 2 against turning while permitting its reciprocatory movement and that by withdrawing the barrel, it may be re-inserted with the projection 213 disposed in the other slot 21o thereby 50 positioning the barrel sleeve in a 60 degree displaced position. Reciprocatory movement of the sleeve 2| 2 is additionally guided and supported by a sleeve 2|4 (Fig. 9) threaded into the end of the sleeve 20|, and it will be apparent that sleeve 55 2|4 will normally prevent withdrawal of the Vbarrel sleeve 2|2 by abutment with the projection 2|3 on the latter. An inner sleeve 2|5 is reciprocatory in the s1eev`e'2l2 andthe former, as best shown by Fig. 15, has three circumferentially 00 spaced slots 2 I6 of the same character as the slot 201 shown by Fig.` 14, and these slots receive radial projections 2|1 at the inner end oi the sleeve 2|2. From this description it will be appreciated vthat the two sleeves may reciprocate 05 relative to one* another and, with the parts arranged as shown by Fig. 9, the legs 206 on the head 203. are in engagement with the projections 2|1 on the sleeve 2|2, while the end portions of the sleeve 2|5 between the slots 2|8 are in en- 70 gagement with the radial projections 20,8 the. head 200. Y

.It will now be apparent that if piston |94 moves to. the left, it will move the head 203 to the left v and the engagement oi' the legs 206 on the latter 7g with the projections 2I1 on sleeve 2|2 will cause the latter to move to the left. The sleeve 2 5 may remain stationary and in abutment with the legs 288 on the cylinder head 280 as the legs 285 and 2|1 on the head 203 and sleeve 2|2 may move axially in lthe slots 2|6 in the sleeve. This arrangement may be reversed by removing the sleeve 2|4 and withdrawing the sleeves 2|2 and 2|5 and then re-inserting them with the projection 2|3 on the outer sleeve disposed in the other of the slots 2|0, and the reason for this selective arrangement is to enable setting of different types of rivets as set forth in the previous applications for patent mentioned.

The outer end of the piston rod |18 has an enlarged portion reciprocatory in the inner sleeve 2|5 and a reduced portion 22| threaded into a tubular jaw operating member 222 that is also reciprocatory in the sleeve 2 |5. 'I'he member 222 at its outer end has a conical inner periphery 223 terminating at the end of the member in a circular opening, and as best shown by Fig. 16, this conical surface has three equally spaced grooves 224 of cylindrical character with the'axis of each cylindrical surface substantially parallel to the conical surface. These grooves respectivelyreceive jaws 225 having outer cylindrical surfaces seated in and movable along the grooves. From this it should be appreciatedthat the jaws may be expanded or contracted by their movement along the grooves 224 while still obtaining full and cylindrical surface contact between theA jaws and the grooves. vIt will be noted that the grooves are not greater than senil-circular in cross section and this is advantageous in that it permits inserting the jaws through the inner end of the jaw operating member 222. If the jaws had to be inserted through' the front opening at the smaller end of the conical surface 223, a larger diameter of the member 222 would be required and this in turn would require larger diameters of the sleeves 2|2 and 2|5 and hence the.barrel of the gun would be larger and could not be inserted in certain places for riveting.

Each of the jaws has an axial extension at its` inner end as indicated at 221 that has a slot 228 therein -for receiving one of three radial projections 228 on the outer end of a tubular sleeve wardly projecting end of the tubular member 230' and this may be' advantageous after the riveting operation in' the event the jaws are unduly wedged in the grooves 224.

For normally urging the jaws toward the left, a

sleeve 23|- is slidable on the sleeve 230 and is proyvided with an annular shoulder 232 engaging the ends of the projections 221 on the jaws. This sleeve is urged toward the left by a coil spring 233 engaging vthe right end of the sleeve and which is. disposed in a recess 234 provided between thel 'larger portion 228 of the piston rod and the tubu.- lar element 230. Between the ange 232 on the sleeve 23| and the end of the piston rod portion 22|, an annular ring 235.0! rubber or the like. is

provided for cushioning the jaws when the rivet pin breaks and -when the vjaws tend to quickly move to the right with respect to the operating member 222 as the result oi' recoil. It may be 'noted here that normally this will be the action 'obtained so that the jaws will automatically free themselves from any wedg'ing engagement with the grooves 224 as a result of recoil force when the pin breaks, but in the event this does-not occur or for any other reason it is desired to move the jaws to the right relative to the member 222, a

the right end of the sleeve 238 maybe gripped from the exterior of the gun and the sleeve pulled to move the jaws.

IThe inner surfaces of the jaws are generally cylindrical with the axis thereof substantially coinciding with the axis of the-piston rod and such inner gripping surfaces are provided with grooves for gripping a grooved portion of the rivet pin. For engaging the tubular part of the rivet, the outer end of the sleeve 2|5 terminates in an anvil 231 that has a tubular projection 238, while the outer end of the sleeve 2|2 terminates in an anvil 239 having. a slightly tapered entry opening 240.

The right and outer end'.of the sleeve 230 has a short sleeve 24| secured thereon, such as by pins or a split ring 242, and this short sleeve has an enlarged bore at its left end containing a coiled lspring 243 abutting the right end of the piston rod |18. I'his arrangement insures movement of sleeve 230 with the piston rod |18 when thel latter moves to the right, so as to hold the lugs or ears 229 at the left end of the sleeve at the right end of the slots 228 in the jaws. In setting a rivet, breaking of the rivet pin causes the ja'ws to move to the right relative to the piston rod |18, and hence relative to sleeve 238, and if the lugs 229 were not at the right end of the slots 228 in 'the jaws, the jaws might engage the lugs and break them oft'. It may be added that the length of the slots 228 to the left of lugs 229 (as shown in Fig. 49) is greater than that permissible movement of the jaws relative to the piston rod and member 222 as governed by the linear space between the shoulder 232 and the left end of the piston rod portion 22|, so that with the lugs 229 normally maintained at the right end of the slots 228, engagement of the lugs with the left end of the slots upon breaking of the pin ordinarily will not occur.

The sleeve 24| enables manual pulling of the sleeve 230 so as to move the jaws backwardly relative to the jawopenings 224. This is advantageous if the jaws ever freeze in the openings, or if it is desired to expand the jaws for any reason.

Now referring to Figs. 11 and 12f, the casting |1| at the upper side of the gun, has an opening 244 in communication with the air line.| 23 and this passageway in turn communicates -with an opening 245- communicating witha valve passageway 248. The passageway 248 has a valve4 241 therein provided with axially directed peripheral spaces 248 to allow air to flow therethrough,` and the central portion of the valve is normally pressed againsta valve seat 248 by means of a; spring 250 engaging the valve and an apertured bushing 25| threaded into the passagewith an opening 252- communicating with the` For unseating the valve 241 aatmosphere. plunger' 253 is reciprocable in a head 254 closing the left `end of vthe passageway 248, and this plunger, as best shown by Fig. 9, is adapted to moved toward the right unseating the valve 241 and this in turn connects the `conduit |28 to the atmosphere allowing air to exhaust.

Referring to Figs. 11, 12 and 13, the passage l 244 is inA communication with the right end of the bore |14 and the left end of bore |15 in the gun and this is effected by providing a longi-A tudinal passageway 285, as shown by Fig. 13, extending through the casting` |1| at one side l of the cylinder bores, and which has its ends plugged and this passageway is in communication with the bores |14 and |15 by means of ports 258 and 251. A second port 288, as shown by Figs. 12 and 13, also communicates with the l right end bore |14 and with the passage 244. Now, if the trigger is pulled, the conduit |23 and the passage 244 are opened to atmosphere and the space at the right side of piston |84 and the left side of piston |84 may' exhaust to atnios` 88 phere. Conversely, whenthe trigger is released and the valve 241 closes, air under pressure may flow into the space kat such sides of the pistons |84 and |84.

Referring also to Figs. 11 and 12', the liquid l5 line 24 is threaded into a bushing 215 disposed in a bore 218 in the casting |1I, and this bushing is held.,against a seal 211 by a threaded bushng 218. The bore 218 in turn communicates with an aperture 218, communicating in turn with a l downwardly directed valve bore 288 extending diagonally into the wall |18 and communicating with the bore |15 by a smaller opening 28| and with the bore |14 at the left end thereof, as indicated at 282. It may be noted that the sides of the wall |18 and pistons |84 and |84 are relieved i so as to insure entry of liquid properly at the adjacent sides of the pistons even though the latter are at the ends of their strokes. The lower end of the bore 288 has an apertured valve seat n 288 adapted to be closed by a ball 284 disposed in a sleeve 285 holding the seat in place and having its upper end enlarged and threaded into the upper end of the bore 288. A spring 288 in the sleeve presses the ball against its seat and the upper end of the spring is held by a cap281 threaded on the sleeve. At `its lower end, the sleeve has one or more openings 288 so that liquid flowing upwardly through the seat 2 88 may pass into the bore 288 at the outside of the sleeve. 5 Thus, liq'uid may flow upwardly from the bore |15 and through the valve, but it cannot flow in the reverse direction, while liquid may flow either to or from bore |14 through the bore 288.

For introducing liquid under pressure to the bore |15 at the right sideof piston |84, a, smaller opening 288 is formed in a tubular member 28| disposed in a bore 282 and this opening. is in communication with the bore 288 by means of an opening 288: vThe left end of the opening 288 .o is normally closed by a small valve element 284 integral with a stem 285 of larger diameter which may slide in the member 28| and it will be noted that around the valve element 284 the end face of the stem is of larger diameter toprovide a greater .5 area for the Aoilto act upon once the element vis unseated from the end of opening 288. The stem 285 is urged toward the right to hold the element 284 in valve closing position by a strong tensile spring 288 disposed in a tubular cap 281 threaded 70. intothe bore 282, and this spring abuts the 'left end nf the cap at one end and at its other end a flange 888 integral with a,,plunger 88| which engages the stem 285. It will be seen that the element 284 will not openI until considerable pressure i*- applied and that once it opensI the ltrgerarea Y against which the liquid may act at the end of thestem 285 serves to hold'the valve open even though the pressure should drop materially. The member 28| is held tightly in position by the cap 281 engaging a collar 882 that in turn engages a bushing 5 383 abutting the left end of the member. Suitable sealing rings 884 may be provided to prevent liquid from seeping between the stern, bore, bushin'g 883 and member-28|.-

When the valve stem is moved by liquid pressure. it moves past a port 885 that communicates with an annular groove 885 in the outer surface of member 28 and the latter communicates with an opening 381 extending to the cylinder bore |15. For the purpose of preventing movement of the stem by a pressure lower than that required to unseat the valve element in .the event any slight leakage occurs past thelatter when it is in closed position, the peripheral surface of the end portion of the stem is provided with very minute p grooves 388 which will allow any oil seeping past the val've element 284 to flow directly into the cylinder. If some means of this character were not provided it is possible in the event of slight leakage past the valve element, that an oil presg5 filled with oil by providing a tapered opening 8|8 in the casting |1| and tapered openings 3|| at each side thereof communicating respectively with the two bores |14' and |15. After filling the system the opening 8| 8 is closed by means of a tapered-plug 3|2 held tightly in place by means of a button 3|8 on aplate 8|4 that is secured by bolts 3 5 to the casting. For the purpose of facilitating removal of the plug 3|2, a screw 8 I5 may be threaded thereinto and when screwed down-,m wardly it may be engaged with the vbase of the opening 3|8 to dislodge the plug and force it upwardly.

The system may be filled with the gun 8 uppermost bypouring liquid thereinto. Liquid iiows u then into the'conduit 24 and into the barrel 28. Air may be allowed to escape from the barrel by providing a screw plug 828 on the barrel 28 (Fig.

1) which may be removed. (During iilling of the system the ball 88 (Fig. 7) must be unseated to 5o allow liquid to flow into the reservoir and this may be done by having air pressure on the head. ||5; or the pin |88 (Fig. 8), could be moved inwardly against the head to unseat the ball. The operator pulls the piston 12 downwardly (Fig. 6)y

by means of rod 8| until the cup 85-is seated at the base of .cap 15 so, as to have the reservoir filled above the piston as shown. The air pressure below piston 12 will be cut oli during this manual movement of the piston and, if desired, a valve in ...o conduit 15 may be utilized for this purpose.

Now referring to Figs. 23 and 24, the rivet may comprise a tubular element 825 having an intermediate portion of smaller internal diameter, an external head 825 and a tubular portion projecting from. the opposite side of the structure to be u riveted and which is indicated at321. The rivet pin, which is indicated at 828, has a break neck 828 of smaller diameter than the remainder of. the pin, a series of locking grooves 838 to the left `im of the break neck, a lshoulder head 88|, a larger left end portion 832, ahead 888, and gripping groovesv 834 at the opposite 'end of the pin. A spreader ring 885 is provided on the larger portion 882 of the pir. and is adapted to increase in l size when the head 333 engages it so as to provide a larger part for bulbing the tubular portion 321 of the tubular member. When the rivet is set, the pin is pulled with the reactionary force applied against the head 326,- and this causes the head 33| first to expand the larger intermediate portion of the tubular member, then the head 333 where the pin projects into the jaws 221| and it l is properly associated with the rivet pin and thus brought into a position in which the anvil portion 238 lies against the outer radial face of the rlvet head 326. With the trigger 258 in closed. position,

- piston |84 and at the left side of the piston |94.

airunder pressure through supply line 44 is applied to the head 43 in the valve 30 shown by Fig. 3, and also against the larger head 39 by air through conduits 80 and |26 (Fig. 4), to the connection on the barrel 20 and passages |21 and|22 (Fig.

8), and then through conduit 42. I'he larger size of head 39 of coursemaintains the valve shown by Fig. 3 at its left position. Also air pressure is applied against head |5 (Fig. 7) and while air pressure is applied against head |02 through conduit ||2.and spring |08 exerts a force against suchhead |02, the larger size of head ||5lis sufficient to hold ball valve 99 open. Also air under pressure holds the piston lI3 in the booster at its left ei.d position. l

When the trigger 258 is pulled, the line |23 is opened to exhaust 'and this .opens allof the above mentioned conduits to exhaust. The metering pins |28 and |724 are so adjusted that air will exhaust more quickly from passageway 8 than it Will from conduits 42 and |26, and this insures closingof ball valve 99 before actuation of the booster control valve 30 shown byvFig. 3,' so as .toavoid a condition where the ball valve would be open when the piston |3 begins to move to the right. Furthermore, the conduit 18 lead,- ing to the reservoir is open Ato exhaust, thereby -wthdrawing this active pressure in the piston.

Pulling of the trigger also exhausts air from the cylinder spacesJ in the gun at the right side of the The piston |3, upon operation of the valve shown by Fig. 3, begins to move toward the right forcing the liquidin the barrel through the conduit 24 and to the gun, and, as will be evidenced 4tremo-Fig. 12, this liquid flows immediately into- 'the cylinder bore |14 land at the left side of the g piston |84. .This causes the'V piston |84 to move toward the right, carrying with it the piston rod |18 and the jaw operating member 222. Positive and forceful contraction of the jawsl results in locking them strongly to the rivet pin and lcon-- tinued movement of the piston |84- will cause movement of the rivet pin while the reactionary force .is applied through the cylinder head 20|),

sleeve 2|5 and anvil 231 to the face of the rivet head 326.v The operations of expanding the tui' bular member intermediate its ends and formation of the bulbed headirom the tubular portion 321 of the rivet ar'eitheneiected in order,l and, after formation of. this bulbed head, very strong resistance is encountered to further movement of the rivet pin andthis causes the liquid pressure in the barrel and in the liquid side to increaserapidly and when this pressure reaches a predetermined amount governed by the valvespring 296, shown in Fig. 12, the valve element 294 will be forced from its seat and the stem 295 will be moved to the left until liquidmay flow into the cylinder bore |15 at the right side of piston |94. Then the piston |94 begins to move rto the left moving with it the outer barrel ,sleeve 2|2 and anvil 239 which forcesthe latter over the rivet head 326 and causes its radial rcontraction to force metal into grooves 330 of the pin. Upon contraction of the head 32B of rthe rivet, resistance to movement of either of the pistons |84 and |94 will further increase,- and this'will cause the liquid pressure in the 'system to buld up to a point where the rivet pin will be so tensioned that it willbreak at the lbreak neck 329. Ordinarily, when the pin breaks, the recoil force on the jaws will cause the jaws to move rearwardly andthe broken part to'pass rearwardly through the jaws and through the piston rod and sleeve 230 and to be ejected from the right end thereof.

If the trigger on the gun is` now released, airv piston |84 and at the left side of piston |94 causing these pistons to return to their original positions thereby forcing the liquid at their opposite sides back into the barrel 20. As will be seen in Fig. 12, |the liquid at the'right side of piston |94 may flow out of the cylinder bore |15 through the passageway 28| and past the ball 284 as the latter will be unseatedby the pressure on the liquid due to the air-pressure at the opposite side of the piston. Release of the trigger causes air pressure to build up quickly below the reservoir piston 12 and at the outer sides of heads ||5 and |02 in the reservoir valve (Fig. 7), andwhile there is vliquid pressure von the outer side of ball 99, the ball will normally be unseated. It may be added that the metering pins in Figs. 'I and 8 are so adjusted that the ball 9'9 is unseated before valve `33 is actuated, or V'in any event -the ball is unseated at leastv simultaneously with initial movement of piston I3 to the'left, and this avoids a condition where the reservoir piston could`not act to supply liquid to and avoid vacuum in the barrel when the piston I3 begins to so move. As soon as valve 33 in Fig. 2 is actuated oy air pressure at the right side of head A38, the valve 33 shifts to the left. thuscausing air to Vexhaust at th'e left side of piston |3 in booster 'and air pressure to build `up at the-right side of thepiston. This releases .the great pressure on the liquid in barrel 20 as the piston rod I6 moves to the left.

y,|94Aifea'chf'gtheir original positions; adjacent ,tend to create a vacuum inthe gun and cause 25 suction o'f 'air'thereinto if therewere any point where air might enter. i' C In th" event jthe operator'` does notrelease the trigger at'the end of the riveting operationpthe -y`pistons Vm4 and |94' wmg'oflcourse, engage the 30 rigid walls at' the endsj'of their strokes and vin this ,eventjthe liquid ,pressure` will continue to buildjup; but, when this pressure reaches a predetermined 'amount,*"tlre valve element |42 and ...stem I 4 shown by Figi 6, vwill move downwardly 35 againstthe action of the "strong spring |52, and this will allow liquid to owinto the reservoir andfit will beappaie't 'that the'valve will remain open eventhough the pressure reduces somewhat owing to the larger size `of the stem. A 40"greate'rA downward movement of the piston 12 in this event isrprovided for if necessary by compression ofthe-spring 81, and ordinarily the sys-,

tem* wilifbev iilled with liquid vto such extent, as `previously'mentioned, to allow liquid to. flow into 45 the reservoir untilthe piston I3 and gun pistons |84 and |94'reach the rightA end of their strokes. The system may be iilled with liquid or replenished.' ifever necessary, with the pistons `|84 and |94 inthe position shown inFig. 9, and o`the booster piston atthe left end of the booster cylinder, Vby removing the`plug`3|2 on the gun and pouring liquid into the opening. Owing to the "fact that air pressure in conduit |26 maintains the balll 99 unseated, the liquid may be pourediri until the gun'passageways, the conduit 24, and barrel 20 are lled. Now, by manually pulling the reservoirpiston 12 down, it being necessary rst to cut oiithe air pressure line 18, `theliquid maybe directed into lthe reservoir 60' until the latter is` illle'd 'to the proper degree.

It fwill*` be recalled that -this manual manipula- 1 tioxifo'ifthe*reservoirv piston 12 is iresisted by" the' spring' 81 i'ffthv piston" is" pulled` downwardly more than a desired amount and this will "insure the 'msn pressure valve on the barrer spess dur-r ing or after the rivet setting operation.

Usel of ,ain pressure 1 at opposite sjides oty the tions ing me? proportion lin-iio'rces isf f ii'nististes aifferentl-form fr econo-ii plunger 51 againsttlie action of spring 6|;it moved by a: -plun'gerf 435|l`-projecting through the With the vparts as shown, the piston`|3 inthe boosterthrough pin 350 holds the valve plunger 51 at, the lleft and noair can flow from conduit 49 to conduit 61. When the valve 30 is operated to exhaust air from the right side of piston |3 and to supplyair to the left side of the piston, air fromthe right side of the piston will rexhaust through the ball valve 68 and when the piston |3 moves, the spring 6| will move the plunger 5 1 until the opening 64 also connects conduits 48 and 61. This also will cause plunger 350 to be projected into the cylinder Il).l

Upon a reverse 'operation of valve 38, air will be introduced into the right end offcylinder I8, and exhausted from the left end and full line pressure will 'acton the left side of` piston |3 until the piston' movesfplunger 350 and through 30 it, the plunger 51 to the position slriown.-V Opening 64 will be closed shortly after piston `I3 engages plunger ||,:and then no further air will be' supplied to the'right end olthe'Y cylinder and the air under pressure in such end ofthe cyl- 35 inder will continue tov expand and move to the piston until it reaches the left end of its stroke. Thus, the air pressure is cut off before the piston |3 reaches the left end of its stroke, thereby` economizing on the air used in returning the piston. 4 Figs. 21 and 22 illustrate'an improved form of jaw arrangement in the gun. Here the jaws 225 engage at their inner ends a relativelyheavy metal inertia ring 354 that in turn engages a sleeve 355 having an enlarged end 356 engaging al spring 351, that in turn engages a shoulder 358 on the rod portion 22|. It will be noted that this sleeve does not pass through to the other end of the piston rod |18. 'I'he spring 351 normally urges the inertia ring 354 and Jaws forwardly andwith the jaws in the normally operative position shown a substantial space 359 exists between the end of rodportion 22| and' the ring. l

'Ihe jaws 225 are also and individually urged inwardly by springs having intermediate coiled portions 360- disposedfinjslots 36| in the'member 222 and each coiled portion is pivotal'. on a pin 362 projecting through `the slot.- Fronto wardly;the coilshave ends.. 363 extending for- Wardlyin recesses 364vin member 222,1` and which i terminate in "radial endsy 385'r projecting' through small openings 366 in suchv ni'eniberl land into" axiai'v grooves 361 in the jaws, 'respectivelys-f The u" other' enqsfof the ons have radial' ends 1368 pro-` jecting intol openings 369inthejaws respectively,

of'theiawsgainst rod tombs 22|: "me 75"" `tapered head 38| for expanding -the segments.

10 388 is occasionally not enough ofa cushion -against such force of the recoil. The ring 388,

however, interposes aninertia force and its weight is such that the rearward throw of the iaws'is slowed up owing to the -fact that the jaws must pick up this weight and carry it with them, and while the jaws and ring both move rearwardly, the recoil force is dissipated 'enough that iinal engagement of ring 388 with the end of rod portion 22| is not damaging to the laws ory ring.

'I'he spring ends 388 and 388 do not interfere with movement of the `iaws andthe ends 388 particularly maintain the laws against turning or circumferentialdisplacement. The ends 388, while normally urging the Jaws rearwardly. are not strong enough to overcome spring 388 so that the latter normally maintains the Jaws seated in grooves 223 "in member222. These ends 388 are provided to move the jaws rearwardly and expand them when it is desired to withdraw an unset rivet gripped by the Jaws, but manifestly it will be iirst necessary to move sleeve 355 rearwardly before the ends 388 can perform this function. To move sleeve 858 rearwardly, an expanding tool 318 may be inserted from the right end of rod |18, and, while any suitable tool may be used. it is shown as comprising a tube 318 having segments 311 separated by slots 318, and a rod 318 threaded into the tube as indicated at 388, and which has a When the segments are expanded into gripping relation with sleeve 358 by turning rod 318 relative to tube 318, the tool may be pulled to the right so as to move the sleeve.

A modified arrangement of the system may be used as shown by Figs. 17, 18 and 19. Instead of using air under a comparatively low pressure. fairly high liquid pressure may be used topper,- ate the booster piston and in this event in order to obtain the required liquid pressure in the barrel. the booster cylinder may be of smaller size as shown. Air may be used to operate the booster valve 38, reservoir valve and to supply air tothe reservoir below its piston. In this construction, the air line 84 is directly connected to the base of the reservoir by a conduit 385. The passage 48 in valve 38, as shown by Fig. 19, also extendsto' the right end of bore 32 and communicates therewith through an opening 388, the effective size of which may be varied by a metering pin 381. With air supplied against both heads 4 3 and 31, the plunger 33 is held in its left position. Conduits 388 and 388 are connected to the cap 8| and conduit 388 extends to the rivet gun, while conduit 388 extends to the reservoir valve (shown by 4 Fig. '1) and iswonnected to the outer end of bore also cause's the ball 88 in the reservoir valve to. become seated. No economizer valve in the cond uit 81 is shown, but it may be used',: and, in fact, the same booster valve, economiser valve, reservoir valve, and reservoir may b'e employe'dasyde scribed previouslyand as shown by Figs. 1 to 8,

inclusive, except that liquid is employed to xnovegffpiston |3.V Inthe constructionfshowi. the llongitudinal aperture 88 in the booster valve, shownu by Fig. 19, is not in communication with the bore 3|: and a liquid inlet 388 is connected to a conduit 38| that extends to a liquid pump 382. For exhausting liquidfrom opposite sides of the piston in the booster, the exhaustports 82 and 83 are connected to an exhaust 1ine383 that extends to the inlet side of the pump 382. With this system, the gun is operated inthe same way by pulling the trigger which exhausts the larger bore portion 32 of'the booster valve causing the valve element 33 to'move to the right andit will be readily understood from the previous description how the liquid under pressure will ilow to one end or the other end of the booster cylinder depending upon the position of the valve.

Although more than one form of the invention has been illustrated and described in detail. it will gbe apparent to those skilled in the art that various modifications may be made without departing from the vscope of the appended claims. v

I claim: v

1. A rivet setting apparatus comprising a closed liquid iluid pressure system including a rivet setting mechanism and a liquid iluid pressure device, movable means in the pressure device for applying pressure to the liquid in the system, movable means in the mechanism and actuated by said liquid pressure for setting a rivet, manually controlled means for effecting movement of said movable means in the prefssure device to apply pressure to the liquid and for reversing :,movementof the movable means after the riveting operation, and means separate from the first means and controlled by operation of as said manually controlled means for injecting liquid into the system at'any 'time during reverse movement of the movable means in the event the space volume` in the liquid system exceeds the a rivet, reciprocable means in the boosting devicev for forcing liquid into the mechanism and applying pressure to the liquid in the system, iiuid lpressure actuated means for reciprocating the rey ciprocable means, a reservoir for liquid on the boosting device, means including a' manually operable means on the mechanism for effecting reciprocation of the reciprocable means, and means separate from the reciprocable means and auto-l matically controlled by said manually operable means for opening said reservoir to communication with the liquid system.

3. A rivet setting apparatus comprising a closed liquid pressure system including iluid pressure responsive riveting means and reciprocable means for forcing liquid against the responsive means to set a rivet, means including manually controlled means for effecting said reciprocable movement of the reciprocable means, a liquid reservoir, a valve separate from the reciprocable means for opening the system to the reservoir. and means controlled by .the manually controlled means'for opening the valve when the movement of the reciprocable means is reversed after the rivet setting operation.

' 4. A rivet setting apparatus comprising a rivet setting mechanism. a liquid iluid pressure boostdevice comprising` a cylinder and'a barrel mailer than'the cylinder. a piston reciprocable in the` cylinder, a plunger reciprocable in the barrelandpmovable withthe piston. means for conducting liquid from the barrel into the mechanism, liquid pressure means for moving the piston, fluid pressure actuated valve means for controlling operation of said liquid pressure means, and means on the mechanism for controlling the fluid pressure actuated valve means.

5. A rivet setting apparatus comprising a rivet setting mechanism, a liquid iluid pressure boosting device comprising a cylinder and a barrel smaller than the cylinder, a piston reciprocable in the cylinder, a plunger reciprocable in the barrel and movable with the piston, means for conducting liquid from the barrel into the mechanismI liquid pressure means for moving the piston, air pressure actuated valve means for controlling operation of said liquid pressure means,

and means on the mechanism for controlling the operation of the valve means previous to or at least simultaneous with operation of the control means.

7. The combination 'in la liquid iluid pressure system, reciprocatory iluid pressure responsive means, reciprocatory fluid pressure means for supplying iluid under pressure when moving in one direction' to the responsive means, a reservoir for liquid, means connecting the reservoir to the system including `valve means and means for positively opening the valve prior to movement of the iluid pressure means in said other direction.

8. The combination ina liquid iluid pressure system, including pressure responsive means `for performing work and reciprocatory means for supplying liquid under pressure to the responsive means, a liquid reservoir for the system, means connecting the reservoir to the system, a valve for opening and closing the reservoir to the system, additional fluid pressure means for actuating the reciprocatory means, and means actuated by the fluid pressure actuating the additional means for actuating the valve.

9. A fluid pressure device comprising uid pres,- sure responsive means, means for introducing fluid under pressure to one side of the responsive means to actuate the latter in one direction, means for introducinggaseousfluid under pressure to the other side of the responsive means to return the latter, and means operable automatically to cut olf the supply of the gaseous fluid "means, the latter automatic means including a valve having a pin portion adapted to be engaged by a part of the responsive means prior to complete return of the latter.

- LOUIS C. HUCK. 

